Question

You have generated antibodies that recognize the extracellular domain of the Ca₂⁺-pump. Adding these antibodies to animal cells blocks the active transport of Ca₂⁺ from the cytosol into the extracellular environment. What do you expect to observe with respect to intracellular Ca₂⁺?

Answer 1

Adding antibodies that recognize the extracellular domain of the Ca²⁺-pump to animal cells blocks the active transport of Ca²⁺ out of the cytosol, leading to an increase in intracellular Ca²⁺ concentration.

Step-by-step explanation:

When you add antibodies that recognize the extracellular domain of the Ca²⁺-pump to animal cells, it blocks the active transport of Ca²⁺ from the cytosol into the extracellular environment. As a result, you would expect to observe an increase in the intracellular Ca²⁺ concentration.

Normally, the Ca²⁺-pump actively transports Ca²⁺ from the cytosol out of the cell, maintaining a low concentration of Ca²⁺ inside the cell. However, when the antibodies block the pump, Ca²⁺ is unable to leave the cell. This leads to an accumulation of Ca²⁺ inside the cell, resulting in a higher intracellular Ca²⁺ concentration.

This increase in intracellular Ca²⁺ can have various effects on cell function, as Ca²⁺ is an important second messenger involved in many cellular processes, including muscle contractions, enzyme activation, and hormone secretion.